Trigger Error

Hi There,
I have created a trigger on a table which should update value in another table. Trigger is created without any error but while executing I get mutate error!
Here is code -

CREATE OR REPLACE TRIGGER holiday_trig
AFTER UPDATE OR DELETE OF status
ON holidays
FOR EACH ROW
DECLARE
totHolidays number;
BEGIN
IF UPDATING THEN
SELECT SUM(workingdays) INTO totHolidays
FROM holidays
WHERE id = ld.id;

A mutating table is a table that is currently being modified by an update, delete, or insert statement. You will encounter the ORA-04091 error if you have a row trigger that reads or modifies the mutating table. For example, if your trigger contains a select statement or an update statement referencing the table it is triggering off of you will receive the error. Another way this error can occur is if the trigger has statements to change the primary, foreign or unique key columns of the table the trigger is triggering from.

i didn't try it but you can try and use autonomous transaction to do the updates (i'm no so sure it will work though).